Q: Shall I put a CD on? とはどういう意味ですか?
A: CD = Music... meaning “Let’s put some music on ..”
Q: it was my dad’s favorite CD? とはどういう意味ですか?
A: QAの全文をご確認ください
Q: you've got quite a CD collection !( otra forma de expresar,gracias) とはどういう意味ですか?
A: It's an expression of amazement at how many CDs someone has collected. It's another way of saying "that's a lot of CDs you've collected!".
Q: CD Baby とはどういう意味ですか?
A: CD Baby is an online music store and music publisher that helps independent artists (creators of music) distribute their music and collect royalties (payments) when other people use / license their music.


Q: I listened to the CD. と I listen the CD. はどう違いますか?
A: The first one is grammatically correct: I listened to the CD.
Q: The CD wouldn't play と The CD doesn't play はどう違いますか?
A: wouldn't = you describe a past event. example, I tried and tried but the CD wouldn't play.

doesn't or won't = present thing happening. example, I'm trying, but the CD won't play!
Q: (with a CD playing) Let's sing along! と (with a CD playing) Let's sing along with the CD! はどう違いますか?
A: "Let's sing along!" and "Let's sing along with the cd!" are the same. The second sentence makes it clear what is being sung along to

(If you hear the cd playing, you don't need to say "with the cd." If the cd isn't currently playing, it's better to be clear and say "with the cd")
Q: He apologized to me for having lost my CD. と He apologized to me for losing my CD. はどう違いますか?
A: I think they can both be used, but the first one has a small nuance regarding the state of the lost CD. The second one sounds more casual and common, though. :)
Q: did you find the CD of my brother's? と did you find the CD of my brother? はどう違いますか?
A: The first one is wrong. The second is correct but sounds odd.

You would say

Did you find my brother's CD?


Q: 在哪个网站可以买到新发布的CD は 英語 (アメリカ) で何と言いますか?
A: Which websites sell new release CDs?
What are some websites where you can buy new recently released CDs?
Q: (私は君に) 今月の25日に発売される〇〇(名前)の新しいアルバム(CD)を送るからたのし楽しみに待っててね は 英語 (アメリカ) で何と言いますか?
A: I am going to send you ___album which will be released this coming 25th . Please wait and enjoy it.
Q: CD release live は 英語 (アメリカ) で何と言いますか?
A: id say promo tour is good
Q: CD is short from compact disk. (Is this grammar correct?) は 英語 (アメリカ) で何と言いますか?
A: @Masa1966: I think you mean "CD is short for compact disc"
Q: CDの値段は高いと思いますか、それとも安いと思いますか? は 英語 (アメリカ) で何と言いますか?
A: Do you think the price of the CD is expensive or cheap?


Q: 1) Some CD players have the function of adjusting speed, like playing at a half speed or 70% of the original speed.

2) You can adjust speed on some CD players. この表現は自然ですか?
A: Alternative (but it's not necessary):
1) Some CD players have the feature of adjustable speed, so that you can play at half speed or at 70% of the original speed.

2) You can adjust the speed on some CD players.
Q: "I will play this CD without interruption."

I am a teacher, and sometimes I pause so students can listen easily.

But this time I won't この表現は自然ですか?
A: As a teacher I think it would sound better if you said, "I'm going to play this CD now so I don't want any interruptions".
Q: About CD players and DVD players,

is it appropriate to call them "playback devices" or "reproduction devices" collectively in specifications or the like although I know they sound combersome?

If not, could you tell me more formal words for "players"?
A: It sounds like you are drafting a legal or technical document, and it looks like you are capable of handling this, so...

I took a brief look at a few digital content licence agreements (Amazon, Netflix, Hulu, Marvel comics, etc.), and none of them try to do what I think you are trying to achieve. Instead, they used defined terms to sidestep the problem you are having.

For example, from the Netflix Licence Agreement:
Netflix provides a subscription service that allows our members to access movies and TV shows (“Netflix content”) streamed over the Internet to certain Internet-connected TVs, computers and other devices ("Netflix ready devices").

Note the use of the term "Netflix ready devices". The other licence agreements I've looked at do roughly the same thing.

So, to answer your original question:
I think "playback device" is fine. Just "device" is also fine.

To take a different approach to the problem you are having:
Instead of trying to come up with a word, it might be better to list out the categories you have in mind, then make it a defined term. For example:
"CD players, DVD players, personal computers, television ("Devices")" (or "Playback Devices", if you prefer)

Then for the rest of your specification, you can just use the word Devices and not have to worry about whether you have picked the right word or not.
Q: "When I was playing a CD for listening English, I fell asleep before I knew." この表現は自然ですか?
A: While listening to a CD to learn English, I fell asleep before I knew it.
Q: This CD player gets choppy when you touch it or cause tremor while it is playing, so treat it gently. この表現は自然ですか?
A: This CD player trembles when you touch it and can get choppy while it's playing, so treat it gently.